How do i get them to back off?

Ok ive recently got a boyfriend and the problem is all my girl-friends are always asking to see him. we went together to meet one of my friends last week, but ended up staying with her for 3 hours! :O and then another hour when another friend arrived. Im not meaning to sound harsh but we do need time alone together and they are starting to really annoy me! Also, my friend didnt ask, but bluntly said to me that she'll meet us again the next time i see him. I dont know what to do because if i say something, i will say it soo badly and they will be offended but they wont get the hint whatsoever :(